Hep needed to ID vintage tube

[Scentral]

Hi All and thanks in advance.
I have a tube from a 1940's guitar amp. No markings on the glass at all. I'm used to seeing tube info printed on the glass itself (6V6, 12AX7, etc..), but nothing here. Written on it's base is, RCA Radiotron Made in the USA. It's a cokebottle style tube. Only other thing it printed is Y6E. Lower half is mirror coated.
Thanks!

 

[Alec_t]

Looks like a double diode.

 

[Minder]

Rectifier tube often can be replaced by silicone S.S. version in some applications.
M.

 

[kellys_eye]

Double diode to me too - possibly and AZ1

 

[duke37]

There are lots of double rectifiers on an IO base 5U4, 5V4, 5Y3, 5Z4, GZ32, GZ33, GZ34, 5R4(GY), AZ31, U183, U50, U52, U54, EZ35, U147 etc. Some of them are directly heated and some indirectly heated.

What is the heater voltage supply?
The 5U4 or 5R4 are perhaps the most likely, both 5V heater/filament.

connections
1 M
2 h
3-
4 a1
5-
6 a2
7-
8 h,k

 

[duke37]

Here is some data for rectifiers."Electronic Designers' Handbook" Landee, Davis, Albrecht.


The scale on the left is rectifier peak resistance.

 

[JWHassler]

https://vinylsavor.blogspot.com/2016/07/tube-of-month-80.html
Definitely

 

[Scentral]

Thanks so much everyone for your posts/assistance. I think it is a 5Y3 rectifier tube. Thanks again!